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3% Hydrogen Peroxide Solution | Pest and Soil Treatment

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Hydrogen peroxide is an environmentally friendly alternative to pesticides, fungicides, and chemical fertilizers. Always use hydrogen peroxide in a diluted form and handle it with care. My go-to treatment for pest and fungus control is either a diluted rubbing alcohol solution or hydrogen peroxide, or a neem oil solution. Anytime I witness a plant in distress–leaf changes, dropping leaves, etc.–I pull out the artillery.  Today I will be going over my experience with hydrogen peroxide.

I usually use it as a foliar (leaf) spray to control pests. I spray the top of the plant soil and potting container to help with fungus and bacteria. I have even poured it through the potting soil to kill off any unusual microbial suspects, like spider mites and fungal gnats. First and foremost, anytime you see pests on a plant, isolate it immediately, then proceed with the eradication process.

Golden Rules When Using Hydrogen Peroxide

Benefits of Diluted Hydrogen Peroxide

Foliage Infestation Pesticide Spray



  1. Do a test area to make sure it doesn’t burn the leaves or delicate root system.  Spot-test an area and wait about three days before spraying the rest of the plant to see if there were any ill effects from the spray.
  2. If the spot-test looks good, proceed. Use a spray bottle to soak the infected plants thoroughly. Make sure to get the undersides of the leaves, top of the soil, and around the pot itself.
  3. Spray once a week or as you see bugs appear.
  4. The hydrogen peroxide will not kill eggs, so you may need to repeat the treatment weekly to remove all the bugs.
  5. Label the bottle and store it out of direct light.

Weekly Preventative Spray

Hydrogen peroxide both treats and further prevents pest infestation. This weaker solution will prevent damage to the leaves and is effective as a general insecticide.



  1. Combine in a spray bottle to thoroughly soak the infected plants. Make sure to get the undersides of the leaves.
  2. Use this mixture as a foliar spray to keep your plants healthy and free from bugs. Spray once a week.
  3. Label the bottle and store it out of direct light.

Bacteria, Fungus, and Infestation Treatment

Hydrogen peroxide helps to kill molds such as powdery mildew caused by any number of fungi. When applied to the plant, the chemical’s two oxygen atoms attach to the fungus and oxidize or burn it.



  1. Pour into a spray bottle. Shake to mix thoroughly. Label the bottle and store it out of direct light.
  2. Spray it on the affected plant daily.

Soil Treatment for Pest Larvae



  1. Water infected plants thoroughly.
  2. The hydrogen peroxide will fizz as it comes into contact with the soil; that’s what kills the larvae and the eggs.
  3. Repeat in 2 weeks for a larger pot, or in 7-10 days for a small pot.
  4. Label the bottle and store it out of direct light.

Grow Strong Roots

Hydrogen peroxide also helps aerate your soil, which should help to prevent future cases of root rot. When it is absorbed into the soil, the hydrogen peroxide breaks down and releases oxygen. These high oxygen levels will make sure your roots are healthy and strong. A healthy root system should be long and untangled, with fuzzy white growth on the main root, which is used for soaking up water and nutrients. Here is a “recipe” to make up and keep on hand for future waterings.



  1. Water mature plants with this solution no more than once a week.
  2. Soak the area around the roots thoroughly.
  3. Label the bottle and store it out of direct light.

There are so many different ways to treat plants, so find a system that you are comfortable with. If something doesn’t seem to work for your case, keep trying other methods. I hope this posting was helpful; it sure helps me! Blessings, amie sue

30 thoughts on “3% Hydrogen Peroxide Solution | Pest and Soil Treatment

  1. Wannabe Vivarium Builder says:

    My plants are all potted with moss on top of the soil. I want to keep both the plants and the moss. How strong can I make the H2O2 solution without damaging the moss? It survived 1/2 c H2O2 to 1 gal H2O… but so did a bunch of tiny flies/gnats. Help!

    • amie-sue says:

      Good morning,

      I don’t have any experience growing moss on top of plant soil, so I am not sure about the max strength of adding peroxide.

      There are many different factors that we can look at when it comes to fungus gnats. Gnats love water so I would make sure that you don’t have standing water in any saucers or cover pots. If you feel that you have an overabundance of gnats, perhaps changing out the soil (doing a hydrogen peroxide treatment to it before introducing the plant to the fresh soil. Do you use gnat sticky traps? Or set out a bowl of water that has 1 Tbsp of each; dish soap, sugar, vinegar. Mix and set in an area where the gnats are. I also add mosquito pellets to my soil – it won’t kill those flying around but it will kill the larva.

      Anyway, those are some of the tacktics that I use to keep them under control. I hope something I mentioned helps. blessings, amie sue

  2. Radha says:

    Does hydrogen peroxide help in eradicating soil mites? I have tonnes of them in all my hard earned composts really don’t know what to do because when I use the compost for sowing seeds they destroy all of them what do I do ?

    • amie-sue says:

      Good morning Radha,

      It sounds like your compost has some sort of infestation. When I spot any type of bugs in my plant soil, I water the soil with a 50/50 solution of water and peroxide. The key is to not dump all the water/peroxide on the soil and call it good. Add some solution, let it slowly start working its way through the soil. Add more, let it soak in, add more… and so on. I do this until it starts dripping water really well from the drain holes.

      The peroxide helps kill off larva plus it brings oxygen to the roots. I am not sure what type of plants you have or the type of mites that you are dealing with but I would stop using that compost for future plants and see if you can treat the ones that already have it.

      Good luck! amie sue

      • Radha says:

        The bugs are soil mites I think tiny white things crawling in the composts I think as you suggested should use new soil or compost for my dahlia seeds and plants.Thank you so much for your prompt reply.Good luck God bless

  3. Donna says:

    Should a person repot the plant after treatment or before?

    • amie-sue says:

      Good evening Donna. There’s really no straightforward answer that I can give. It all depends on the severity of the issue, what treatments you use, and the overall health of the plant. blessings, amie sue

  4. Donna says:

    Should a person repot plant after treatment with fresh soil?

  5. AMS says:

    If I do a soil flush treatment (no plants in my pot, I just have this habit of reusing potted soil),should I rinse of my h202 solution with water afterwards? Or I can just let the h202 solution evaporate until the soil is dry and then I can use it for planting again?

  6. Monica says:

    We just bought a new home with 2 raised garden beds. They are full of those little ant/gnat looking bugs, can I just soak the soil with 50/50 peroxide mixture to eliminate them?

    • amie-sue says:

      Good morning Monica,

      I personally don’t have experience with ant/gnats and gardening so I can’t safely advise you. I wish you the best of luck. amie sue

  7. […] hydrogen peroxide can be used to kill pests, it is not a chemical pesticide in the stricter sense of the term. Once it has done its work, it […]

  8. ANNE TWINE says:

    Hello, I can only get 9% hydrogen peroxide, would it be ok to use if I dilute it 3x more than the weaker version

  9. Liza Kato says:

    Hi.Can i use hydrogen peroxide to have the leaves back of my small trees that was bugs by insects.18 pcs had no leaves for 5 months.5pcs of blueberries,2pcs of rasberries,2 pcs of grape fruits,2 pcs of kiwi fruits,2pcs apple fruits.I do all my best.I spray it with healthy vitamins but the leaves never came back.Help me please.

    • amie-sue says:

      Good day Liza,

      I really don’t know about using hydrogen peroxide on the fruiting plants/trees to get the leaves back on them. What kind of insects are attacking your fruit plants? Is the fruit ok and it’s just the leaves that are affected? How old are the plants? amie sue

  10. Sib says:

    Hi Amie-Sue. Thank you for all your good advice here! I have been growing my first cole crops ever this year, and the broccoli has outgrown my row cover! I am hoping to avoid root maggots and other cole loving bugs until I can get a larger row cover fabric. Meanwhile, do you think a drench would help protect against root maggots?

    • amie-sue says:

      Good day Sib,

      I am sorry to say that I don’t have an answer to your question. I don’t have any experience with your situation. I would suggest reaching out to your local agriculture department to see if they have any advice. Best of luck! amie sue

  11. Denise says:

    How do you mix H2O2 & Neem? You mentioned that in your article

  12. Annamarie says:

    You have been very helpful and I appreciate your outcome I have two very tall plants and I just noticed that they are losing leaves and there are bugs on them so I’m going to use
    peroxide and dilute it with water thank you very much

  13. Laura says:

    Hello Denise, would this work for thrips on my monstera?

    • amie-sue says:

      If it were me, I would clean the plant and treat with Neem oil monthly until you don’t see any signs of them. You can sprinkle diatomaceous earth on the soil, along with yellow sticky tape used to trap insects. Make sure you quarantine the plant until you don’t see any signs of thrips so they don’t spread to other plants. Good luck! amie sue

  14. Donnie says:

    Your article is the most informative one I’ve read! Thank you for this information.

  15. Stefano says:

    Can someone be more explicit,, because i cannot understand nothing. My question it’s how much hydrogen peroxide(MLS) use per litre water. Can someone be more explicit and clear please. Thanks

  16. Stefano Cercel says:

    Can someone be more explicit,, because i cannot understand nothing. My question it’s how much hydrogen peroxide(MLS) use per litre water. Can someone be more explicit and clear please. Thanks

    • amie-sue says:

      Hello Stefano,

      Foliage Infestation Pesticide Spray


      1 cup 3% hydrogen peroxide
      1 cup distilled water


      There is basically 4 cups to a liter.
      The recipe above is 50/50. Therefore, if you are using 1 liter of water, you would use a liter of hydrogen peroxide.

      I hope this helps, amie sue

  17. Lisa says:

    Where do you get 3 percent hydrogen. The store it 70/30 or80/20 what is 30 percent and how do you make it

    • amie-sue says:

      Good morning Lisa,

      If you google 3% hydrogen peroxide you will see there are tons of manufactures and places that sell it. I am not sure what you were seeing the store. Amazon has it for quick reference. amie sue

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